order by 后怎么跟变量，哈哈原来这样简单

CREATE PROCEDURE procTest1
 @p1 varchar(40)
AS
if  exists(select * from syscolumns where id=object_id('test1') and name=@p1)
 exec('SELECT * from test1 order by '+　@p1)

这样, @p1错了就不会执行select了